DJ is pretty clearly going to be the "Lando" character of the film. Shifty and untrustworthy friend from the past, he will ultimately aid the heroes in their time of need. I think we can pretty safely say he'll be at the posh Space-Casino (aka Cloud City II) and the Heroes (except for Rey who will be with Luke (=Yoda II) training on that deserted island (=Dagobah II)) will find themselves going there seeking help after a First Order attack on the Resistance base/fleet leaves them on the run. That aforementioned First Order assault will likely feature the wobble-speeders (=Snowspeeders II) fighting against the Gorilla Walkers (=AT-AT IIs) on the red-sand planet (=Hoth II).